By Melissa Reynolds

What would result in a prestigious career in studying the diversity of freshwater ecosystems and providing methods of monitoring water pollution began with trips into the wilderness on collecting excursions as a young child.

Born in Topeka, Kansas in 1907, Ruth Patrick developed an interest in natural sciences early on through collecting worms, mushrooms, plants and rocks on trips into the woods with her father and sister.

Dr. Patrick received a degree in biology from South Carolina's Coker College in 1929, as well as an advanced degree from the University of Virginia where she did her doctorate on diatoms, which are groups of microscopic algae. In 1933, she began as an unpaid researcher and volunteer curator of the microscopy department with the Academy of Natural Sciences. In 1945, she started studying diatoms as a paid position.

Dr. Patrick went on to become the curator of the Academy's Leidy Microscopial Collection in 1937 and reignited her research in diatoms. She began by grouping the diverse collections into a single diatom herbarium, as well as expanding the collection through her own acquisitions. She demonstrated how to maintain different forms of algae in water.

The diatom herbarium quickly became one of the largest and most important collections in the world, largely due to Dr. Patrick's work, as well as to her creation of a new Taxson file and Literature Citation file, which was a collection of listings and references of newly named diatoms and all scientific publications pertaining to the diatoms.

It wasn't long before Dr. Patrick's work showed her that the algae in the streams were an indication of the streams' environmental condition, especially whether or not they were polluted. She also concluded that insects and fish could also indicate water quality.

Her work, known at the Patrick Principle, showed that biological diversity holds the key to understanding the environmental problems affecting ecosystems.

Dr. Patrick went on to found the Limnology Department at the Academy of Natural Sciences to further her studies on water pollution. One of the first studies they undertook was the 1948 survey of the Conestoga River in Pennsylvania. Further studies were done in South Carolina, Tennessee and Texas before the centre was renamed the Patrick Center of Environmental Research.

In the 1950s, Dr. Patrick began a relationship with DuPont by assessing the ecological status of the Savannah River near the chemical company's nuclear power plant.

Dr. Patrick's milestones continued to grow. In 1975, she became the first woman and the first environmentalist on the DuPont Board of Directors, as well as being an advisor to President Lyndon B. Johnson on water pollution, and President Ronald Reagan on acid rain.

In 1973, she became the first woman chair of the Academy of Natural Sciences' Board of Trustees, and later formed the Environmental Associates. She made her mark as a teacher, too, by teaching limnology and botany at the University of Pennsylvania for more than 35 years, publishing more than 200 papers and books.

In 1975, she received the John and Alice Tyler Prize for Environmental Achievement, and was awarded the National Medal of Science by President Bill Clinton in 1996. Both the American Society of Limnology and Oceanography, and the National Council for Science have awarded her lifetime achievement awards. Other awards on her list are the Pennsylvania Award for Excellence in Science and Technology, the Eminent Ecologist Award from the Ecological Society of America, the Gold Medal from the Royal Zoological Society of Belgium, and the Benjamin Franklin Award for Outstanding Scientific Achievement. In addition, she holds many honorary degrees from colleges and universities throughout the United States.

During her extensive career, Dr. Ruth Patrick has ventured into more than 850 rivers around the world for her research and her quest for clean water.